Electrical air heater



Aug. 13, 1929. HICKS 1,724,585

ELECTRICAL AI-R HEATER Filed July 25, 1927 F I E 23 :iSRii INVENTOR W/W/am M a/ey f/lclj A TTORNE YS Patented Aug. 13, 1929.

I UNITED STATES PATENT OFFICE.

WELIAM WESLEY HICKS,

0] SAN FRANCISCO, CALIFORNIA, ASSIGNOB IO m NATIONAL COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OI DELA- WARE.

ELECTRICAL AIR HEATER.

Application filed July 25, 1927. Serial 170. 208,125.

This invention relates generally to electrical air heaters for domestic purposes.

It is a primarfy object of this invention to greatly simpli y the constructlon and cheapen the cost of manufacture of electrical air heaters,

It is a further object of this invention to devise a novel form of electrical air heater which may be secured to the wall of a room without the necessity of first providing a recess therein.

Further objects of this invention will appear from the following description in which I have set forth the preferred embodiment of my invention. It is to be understood that the appendedclaims are to be accorded a range of equivalents consistent with the state of the prior art.

Referring to the drawing:

Figure l is a front elevational view illustrating an electrical air heater constructed in accordance with this invention.

Fig. 2 is a cross sectional view taken along the line 2-2 of Fig. 1.

The heater of this invention is of the general type which makes use of a metal housing within which one or more electrlcal heating elements are disposed, whereby convective currents of air within the roommay circulate into and out of the housing. In this particular case the housing includes a front plate 11 which may be constructed of either pressed sheet or cast metal. Instead of using additional side, and top and bottom walls, the front plate is bulged forwardly as shown in Fig. 2, so that the housing is completed merely by the addition of a suitable metal back plate or back wall 12. Secured to the front plate 11 and disposed within the housing formed by the front and back plates, there is an open front shell 13 within which is positioned one or more electrical heating elements 14. lVhile a variety of electrical heating elements may be incorporated with the device, the element disclosed gives good results and comprises a relatively fiat upstanding refractory support 16 which may rest upon the bottom shelf 17 of shell 13. This refractory support is retained in spacedv relationship to the vertical wall 18 of shell 13, and may have its upper portion steadied as by means of spacing member 19. The periphery of the support is grooved both for the purpose of providing an augmented radiation area and to provide means for positioning the convoluted resistance conductor 21.

In electrical air heaters which have been constructed in the ast, shells similar to shell 13 shown in the drawing have been employed, but these shells have been constructed as a separate member and then attached to the rear face of a front grill, as shown for example in my Patent No. 1,518,- 067, issued Dec. 2, 1924. In this invention I propose to make the shell 13 as an integral part of the front plate 11 as shown. In case the front plate is a casting, the shell 13 is cast together with the front plate to form an integral piece, or in case sheet metal is employed, one single sheet may be pressed out to form both the bulged front plate and the shell 13. It is obvious that this constructlon will effect a substantial saving in the cost of manufacture of an electrical air heater, and at the same time will produce a more rugged structure. Only one manufacturing step is required to construct both the shell and front plate, and the necessity of assembling these elements is obviated. The unction between the shell 13 and the front plate may be formed with a recess or shoulder 22 to provide convenient means for positloning a metal guard 23.

With a heater such as described above considerable heat may be transferred to the metal back wall 12 unless proper provision is made for carrying away such heat by convection currents of air. For this purpose a plurality of apertures 26 are provided in the front plate 11 below the shell 13, and another series of apertures 27 above the shell. These apertures permit convection currents of air to pass into the lower portion of the housing, to flow upwardly between the shell and the back wall 12, and out thru the upper portion of the housing. Direct conduction of heat from the shell 13 to the side portions of the front plate 11 is preferably minimized by providing rows of elongated apertures 28 ad- 'jacent the junction between the front plate and the shell 13. This construction is preferable because of the ease with which heat may flow from the shell to the front plate, due to the integral construction.

For controlling the current supplied to the heating elements I have shown a suitable electrical switch 29 which is preferably positioned within the housing below the heating element. As a means for positioning th s switch I have shown a metel casing 31 whicn is'preferably formed integral with the lower portion of the front plate 11. The control the switch is preferably substanknob 32 of tially flush with the outer edge of casing 31,

and the front face of casing 31 is preferably closedas by means of an inwardly dished member 33. y

In installing a heater such as described above, the back wall 12 is secured flat against the wall of a room. For example it is only necessar to drive a nail or screw into the wall an then suspend the device by engagin the nail or screw in the slot 34 provided in ack wall 12. The exposed surface of the r I rified enamel trical heating 7 when fixed to awall above.

amount of heat is radiated into the room, the

remainder of the heat being absorbed by convection currents of air. The bulged construction of the front plate makes possible the formation of a heater housing with only the addition of aback wall, and likewise makes a heater which is neat in'appearance of a room as described I claim: v

1; In an electrical air heater, a metal front plate, a metal front plate bulged outwardly, a backwallv secured across the rear face of said plate therebyforming a housing, a shell disposed within the housing and formed' 1ntegral with said front plate, said shell be n spaced from said back wall, and electrlca heating, means disposed within the shell, saidfront plate having perforations below and said front plate,

' front plate,

above the shell for passage of convection currents of air.

- 2. An electrical heater of the wall type comprising a metal frontplate bulged outwardly, a backwall secured to said front plate and defining a housing together with a shell spaced from said backwall and having its open front side exposed to the intermediate portion of said an electrical heating element disposed in said shell, and means for suspending said heater upon 'a fiat unrecessed surface of a room wall.

3. An electrical heater of the wall type comprising a metal front plate bulged outwardly, a backwall secured to said front plate and defining a housing together with said front plate, said front plate having openings in the upper and lower portions by enamthereof for passage of convective currents of'air and also having anopen intermediate portion, an electric heatingelement cooperatively disposed in front of said-backwall and exposed thru the open intermediate portion of said front plate, and means for suspending said heater upon a flat unrecessed 7 surface of a room wall.

4. An electric air heater'for wall attachment, an integral metallic front portion outwardly bulged and formed with a central depression in the'bulged portion providing a recess, a flat plate secured to the rear face of the front portion in s aced relation to that part of the front portion formed by the depression, said plate bein apertured to receive supporting means or the heater, and electrical heating means mounted in the depression formed in the front portion, said front portion having air circulating apertures'formed therein around the central depression toprovide circulation between the front and back portions 1 5. An electric air heater for wall attach ment, an integral metallic front portion outwardly bulged and formed with a central depression in the bulged portion providing an outwardly facing shoulder and a recess, a guard member mounted on the front por-' tion in engagement with the outwardly facing shoulder, a fiat plate secured -to the rear face of the front portion in spaced relation to that part of the front portion formed by the de ression, said plate being apertured to receive supporting means for the heater, and electrical heating means mounted in the de ression formed in the front portion, said ront portion having air circulatin apertures formed therein around the centra de ression to rovide circulation between the ront and ack portions.

6. An electrical heater for attachment to an unrecessed wall comprising a front plate bulged outwardly, a flat back plate extending across the rear edge of the front platethereby forming a housing with the front plate, said back plate being adapted for attachment against an unrecessed room wall, a shell secured to the front plate intermediate the sides and ends of the same, the rear wall of said shell being spaced from said back wall and thus forming a flue for convection currents of air, and an electrical heating element disposed in said shell, said front wall having openings in the same above and below said shell for passage of convection currents of air.

In testimony whereof, I have hereunto set my hand.

WILLIAM-WESLEY HICKS. 

